Coplanar waveguide resonator and coplanar waveguide filter using the same

Abstract

A coplanar waveguide resonator (100a) has a center conductor (101) formed on a dielectric substrate (105) that has a line conductor (a center line conductor) (101b) extending in the input / output direction, a ground conductor (103) that is disposed on the dielectric substrate (105) across a gap section from the center conductor (101), and a line conductor (a base stub) (104) formed as an extension line from the ground conductor (103), and a part of the base stub (104) constitutes a line conductor (a first collateral line conductor) (104a) disposed in parallel with the center line conductor (101b).

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a coplanar waveguide resonator and a coplanar waveguide filter using the same. More specifically, it relates to miniaturization of the same.[0003]2. Description of the Related Art[0004]Recently, a coplanar waveguide filter using one or more coplanar waveguide resonators has been proposed as a filter used in a transceiver device for microwave or millimeter wave communications. A coplanar waveguide resonator has a line conductor (a center conductor) having an electrical length equivalent to a half wavelength or a quarter wavelength and a ground conductor disposed across a predetermined space from the center conductor that are formed on the same surface of a dielectric substrate. Thus, for example, the circuit pattern is formed on only one side of the dielectric substrate, and no via hole is needed to form a short-circuited stub. As a result, the coplanar waveguide resonator has advantages ...

AI Technical Summary

Benefits of technology

[0016]The resonance frequency f1 of the center conductor can be split and the center conductor can be made to resonate at a frequency f2 lower than the frequency f1 by providing the base stub having the first collateral line conductor. This means that, in designing and fabricating a coplanar waveguide resonator having the resonance frequency f2, a center conductor having a physical length corresponding to an electrical length equivalent to a quarter wavelength or a half wavelength at the resonance frequency f1 can be used. That is, according to the present invention, the total length of the coplanar waveguide resonator can be reduced. In addition to the reduction in total length, since the coplanar waveguide resonator has a simple structure in which the base stub is additionally provided in the gap section between the center line conductor and the ground conductor, the footprint of the coplanar waveguide resonator on the dielectric substrate is reduced. Therefore, according to the present invention, the coplanar waveguide resonator is downsized compared with conventional coplanar waveguide resonators, and since such coplanar waveguide resonators are used, the coplanar waveguide filter is also downsized compared with conventional coplanar waveguide filters.

Problems solved by technology

However, the area of the center conductor is increased to increase the capacitance at the part at which the electrical field is concentrated, and therefore, it is difficult to reduce the footprint of the quarter-wavelength coplanar waveguide resonator on the dielectric substrate, while the total length of the coplanar waveguide resonator can be reduced.

However, the quarter-wavelength coplanar waveguide resonator requires an area on which the center conductor having a physical length corresponding to an electrical length equivalent to a quarter wavelength is disposed, and therefore, it is difficult to reduce the footprint of the quarter-wavelength coplanar waveguide resonator on the dielectric substrate.

As described above, even if the total length of the coplanar waveguide resonator can be reduced, the coplanar waveguide resonator cannot be sufficiently miniaturized.

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